Hello, I am using the trousers-0.3.1 library for a set of programs. These programs are involved in verifying the software stack of a machine having a TPM chip. I am using many functions in the trousers library such as Tspi_TPM_Quote(), Trspi_Verify() etc.
I was measuring the time taken by these functions. The observed values were a bit strange. Since I could not find an explanation myself for these values, I thought I should post here. I would be grateful if someone could throw some light upon this. (1) The time taken by the function Tspi_TPM_Quote() is 0.732 seconds. Is this function expected to require so much time? Going through the source code, what I found was that tpm_quote() fills up the 'quoteinfo' structure with the requested PCR values and the externally supplied "nonce". Can anyone explain which sub-operations of tpm_quote are time-consuming? (2) One of the program loads the AIK which is stored as Blob in a file. (This AIK key was generated by the "identity.c" program code available at http://www.privacyca.com/code.html#aikquote) The function that loads the AIK, namely, Tspi_Context_LoadKeyByBlob() takes 2.5 seconds to execute!! Any reason why the loading of AIK into TPM memory would take so long to complete? Is there any way to optimize this time, for example, by using an already loaded key from the previous run of the program? I saw some code in load_key_init() function in tcs/tcs_key.c file that first checks whether key loaded by another thread can be used. But it does this provided the key blob is not encrypted. I think the key blob file produced by "identity.c" is encrypted. So does this mean that there is no way to re-use an already loaded AIK ? I appreciate any help. Thank you, Amruta ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ TrouSerS-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/trousers-users
